If you’ve spent time with Rails, you’ll already know that Formtastic is ace, and constructing forms using the SemanticFormBuilder keeps your code neat, and the output sensible and semantic.

More often, I find the need to include a control in my forms that allows the user to find and select a single LatLng, and, up until now, I’ve been adding in hidden fields and creating js that allows me to present a map control.

In an effort to reduce this duplication, I’ve built a Rails plugin for Formtastic that provides a new map_input and multi_input function, which means if you have a lat/lng pair, and you want to let the user fill out these values, all you need do is:

<% semantic_form_for @venue do |f| %>
  <%= f.multi_input :latitude, :longitude, :as => :map %>
<% end %>

Note you’ll also need to include the Google Maps script in your header:

<script type='text/javascript' src='http://maps.google.com/maps/api/js?sensor=true'></script>


You’ll need Formtastic

Install Maptastic as a plugin:

script/plugin install http://github.com/MattHall/maptastic

Or as a gem:

gem install maptastic-form


This plugin is under development. It’s pretty simple, and patches are very welcome.

The Repo is available on GitHub.